According to forecasts from the Portuguese Society of Allergology and Clinical Immunology (SPAIC), until 29 May, the concentration of pollen in the air will be high in all districts of mainland Portugal, especially for olive, pine, birch, cork oak and oak trees and grasses, plantain, sorrel, nettle and urticaceae (including pellitory).

In the district of Lisbon, the highest concentrations of pollen are in the capital and in the municipality of Setúbal, for the same trees and herbs.

In the Autonomous Region of Madeira, forecasts indicate low concentrations of pollen in the atmosphere, particularly in cypress, pine, eucalyptus trees and also grasses, plantain, chenopodium, sorrel, nettle and urticaceae (including pellitory).

In the Autonomous Region of the Azores, especially in Ponta Delgada, the concentration of pollen in the atmosphere will also be low, but with emphasis on cypress (and/or cryptomeria) and pine trees and grasses, plantain, nettle and urticaceae (including pellitory).